Thermostatic switch for incubators



A. M. GOLDBERG 'mauosu'nc swITcH FOR INouBAToRs med Aug. 28. 1922 IN VEN TOR. 6,9750@ M 6b; a@ ma) ATTORNEY.

Patented Aug. 16, 1927. y

UNITED STATES ARTHUR M; .GOIinBERen OrINnI'ANArOLIs, INDIANA, Ass'I'GNn lTo nIinOTRIo CON- TROLLER COMPANY, or INDIANAPOLIS, INDIANA, A CORPORATION OrINnIANA.y

TERMOST'ATIO SWITCH 'rOI'tINoU'BA'TO'nsp App'iication are@ August asgia'z". SeriaIN'. 584,662.

It is the object of my invention to provide a thermostatic switch, particularly for incubators,l which switch will be sensitive, rugged, inexpensive to make and install, and

easy to adjust both for temperature and for different-level strata of air.

The accompanying drawing illustrates my invention: Fig. 1 is a front elevation of a thermostatic switch embodying my invention, with the supporting base in section, and with a fragment of the associated incubator also in section; and Fig. 2 is a plan of the:

thermostatic switch with its supporting base.

' My thermostatic switch comprises a hori- Zontal frame 10 with upstanding fingers 11 and 12 at its two ends and with an adjusting screw 13 projecting upward through it at an intermediate point. The finger 11 has one end of a lever 14 pivoted to it, and the other end of such lever extends close to the finger 12 andk there has an upturned end 15. A second lever 16 lies above the first lever 14, and is pivotally mounted on the linger 12 so that it is engaged near its fulcrum by the upturned end 15 of the lever 14. The lever 16 extends to and over the finger 11, and its free end and an out-turned flange 17 of the nger 11 carry two co-pending contact points 18 and 19, which are suitably insulated from the parts which carry them and have binding screws for the attachment theretoof flexible conductors 2O and 21 respectively. A sealed hollow jthermostatic wafer or capsule 22 preferably formed of two circularly corrugated disks joined at their edges to enclose a. body of fluid,'lies between thelever 14 and the frame 10; andv has its center on its upper side fixed'. to an intermediate pointon the lever 14, and is a button 23 which rests upon the upper end of the adjusting screw 13.

Upon increases or decreases of temperature, the fluid within the thermostatic wafer 22 expands or contracts. `When it expands, with its button 23 resting on the screw 13, it forces upward the lever 14, which in turn forces up the lever 16 with a magnified movement because of the movement-increas- -ing arrangement of the two levers. When the thermostatic wafer cools and contracts, it lets the lever 14 descend, and thereby lets the lever 16 descend much more rapidly. By this movement of the lever. 16 up or provided at its center on the under side with down, 'the contacts 18 and 219 are separated l' orbrlo'ught together; and the co'ntrolis very sensitive, so that the making or breakingl of the circuit controlled by such contacts occurs upon a very slight change of' temperature.

The temperature at which the making or breaking of the circuit occurs may be controlled by adjusting the screw 13; which is easily accessible, may be operated without touching either lever 14 or 16 or any part carried thereby, and in its adjustment does not turn or otherwise change the position (except in height) of the thermostatic wafer 22.

The frame 10 and the parts carried thereby are supported by the finger 12, which has two laterally projecting perforated lugs 25 through which projects a post 26 projecting downward from a supporting base 27 attached to the under face of the top 28 of the incubator 29 by attaching screws 30. The whole switch may be adjusted vertically on the post 26 to position the thermostatic wafer 22 in the desired stratum of air near thetop of the incubator, so that it will respond; most accurately to the variations in the actual conditions to which the eggs are exposed; and when adjusted in proper position maybe 'fastened there by set screws 31 projecting through the lugs 25 into engagement with the post 26.

The base 27 serves not only as a support for theswitch and as a mounting for the post 26, but is ina-de hollow on its Vupper surface to serve as a housing for a condenser 35; and serves also as a mounting for' three binding posts 36, 37, and 38, at which all the necessary connections for the heating and controlling circuits are made. The binding posts 37 and 38 at their inner ends are connected to the two terminals of the condenser 35. At their outer ends, these two binding posts also receive the opposite ends of the wires 2O and 21 from those which are attached to the two switch contacts 18 and 19. The two binding posts 36 and 37 receive the. terminal wires 39, and 40 from the heating element 41 which heats the incubator 29 and is arranged at any convenient point in such incubator. The` two binding posts 36 and 38 also receive the, ends of the leading-in wires 42 and 43 from the supply circuit 44 When the switch contacts 18 land 19 are in engagement, the heating oii'euit is Completed 'through the Wires 413 and 20, the contacts 18 and 19, the Wires 21 and 40, the heating element 41, and the wires 39 and 42. Vhen the contacts 18 and 19 separate, they break this circuit, and the are is suppressed by the condenser 35.

By this Construction, I make a switch which is adaptable for diiferent styles of inoubatoi's, which can be sold and installed as a unit and conveniently. and readily adjusted to inset conditions, and which contains Within it all the necessary parts for making the connections for the electric circuits.

I elailn as my invention:

A thermostatio switch, comprising a base, a supporting post carried by said base, a traine adjustably mounted on said supporting post and adjustable to different positions alongthe post, and a switch and thermostatio operating ineaus for the switch completely carried by said adjustably mounted traine.

In Witness whereof, I have hereunto set iny hand at Indianapolis7 Indiana, this 11th day o1 August, A. D. one thousand nine hundred and twenty two.

ARTHUR M. GOLDBERG. 

